1. Technical Field
The present invention relates to a method of manufacturing a semiconductor module having an integrated structure, by mounting a semiconductor chip formed with a semiconductor power element on a is plate having cooling fins, followed by resin-molding the semiconductor chip and the plate for integration, and relate to a semiconductor module having a structure suitable for the method, the method being favorably applicable, for example, to a semiconductor module such as of a two-in-one structure in which two semiconductor power elements, i.e. an upper arm (high-side element) and a lower arm (low-side element), are resin-molded.
2. Related Art
A patent document JP-A-H11-204700 discloses a semiconductor module having an integrated structure, which is provided by mounting a semiconductor chip formed with a semiconductor power element on a plate having cooling fins, followed by resin-molding the semiconductor chip and the plate for integration. In this semiconductor module, a semiconductor chip is mounted on a plate having cooling fins via a sheet of insulating material and a heat spreader. The heat spreader is configured by a metal block made such as of copper. The semiconductor chip is resin-molded together with the heat spreader and the insulating material so that the entirety is covered with the mold.
In a semiconductor module having the structure as disclosed in JP-A-H11-204700, a plate having cooling fins is insulated from a semiconductor chip, for example, using an insulating material. In such a structure, a heat spreader is adhered to the plate having cooling fins using resin molding after mounting the insulating material on the plate having cooling fins and then further mounting a copper block and a semiconductor chip. Specifically, parts including the heat spreader are adhered to the plate having cooling fins using the heat and the molding pressure resulting from the resin molding.
However, in the case of a semiconductor module in which an adhesion process is performed as mentioned above, an insulation testing step for checking the presence or absence of pinholes in a resin sheet is carried out after resin molding. Therefore, in the event that insulation failure is found in the course of the insulation testing step, the completed semiconductor modules in question all have to be discarded. From the viewpoint of saving resources, discarding completed semiconductors in this way is not favorable.